The flashing devices are widely used on shoes, clothes or backpacks for purposes of decoration and warnings to ensure safety of the users. The working principle of electroluminescent: the fluorescent material excited by alternating current electric field emits high efficient cold light that contains no ultraviolet rays, that is, the alternating electric field generated by the alternating voltage imposed on the electrodes excites the electrons, the excited electrons knock the fluorescent material and causes the jump, change or compounding of the energy levels of the electrons which then emits high efficient cold light. The phenomenon is called electroluminescence. Electroluminescent elements are developed according to the above principle. Having a full range of colors, electroluminescent elements are widely used as LCD back light source, in clock, watch, toys, electronic giftware, Christmas lights, advertisement signs, emergency marker lights, door signs and plates, vehicle license plates, instruments and meters and night lights and so forth.
A flash driving device of the existing technology is shown in FIG. 1, which is composed of power supply, controlling IC, electroluminescent element driving unit, and electroluminescent element. The power supply feed the controlling IC and the electroluminescent element driving unit, the controlling IC supplies a flash to electroluminescent element driving unit which in turn drives the cell to display flash according to the signals of controlling IC.
The physical luminescence of the electroluminescent element requires alternating (AC) voltage as its working voltage, the optimum range of which under current technical standards is from 50V to 110V, with the frequency range from 400 Hz to 1200 Hz. This imposes a high demand on the DC power supply which needs to be converted to AC voltage to drive the electroluminescent element. Most flash devices use batteries as power supply due to limited installation spaces on the articles like shoes and clothes and the limited weight of the device themselves. When DC 3-6V is raised to AC50-110V, there exists the problem of the conversion efficiency which prevents the unchargeable batteries from having a satisfactory service life, thus the application of the colorful electroluminescent elements in the flash devices failed to reach its ideal potential.